Summary/Abstract Funds from NIGMS are requested for the purchase of an Amersham Typhoon IP phosphorimager, associated storage phosphor imaging plates and cassettes, and software licenses for data analysis. The institutional commitments from the University of Pittsburgh and its Department of Biological Sciences toward this endeavor include trading in the old imager ($5,000), purchasing the computer to run the instrument (~$2,500), contributing $6,000 to defray the cost of the request, and providing the maintenance contract. The imager scans storage phosphor screens up to 34 x 46 cm quickly and to high resolution, facilitating the collection of quantitative data over a large dynamic range. The radionuclide-based experiments in the Berman and Brodsky laboratories in the Department of Biological Sciences are currently imaged using an >8-year old GE Typhoon FLA 7000 phosphorimager, whose resolution and dynamic range are significantly lower than those of the request instrument. This imager uses glitchy, but no longer supported, software. Both the hardware and software routinely malfunction, resulting in days of wasted time; it also only accommodates exposed gels that are up to 20 x 40 cm. The request of funding to purchase the Amersham Typhoon IP phosphorimager is linked to grant R01 GM116889 to Dr. Andrea Berman and grant R01 GM075061 to Prof. Jeffrey Brodsky. Each aim described in grant R01 GM116889 to Dr. Berman necessitates the use of trace levels of radioisotopes, which allow for quantitative assessment of high-affinity interactions. These analyses are critical first-steps in identifying appropriate co-crystallization targets and in characterizing biological function. Thus, a reliable, functioning phosphorimager with high sensitivity is essential to the successful completion of the aims.